A photoconversion material may be used to convert incoming photonic energy into electrical energy. Examples of photoconversion materials include solar cells, Stark cells and thermophotovoltaic cells. A Stark cell can be modeled as a photodiode in sheet form (a large expanse of photodiode junctions merged into one) that behaves like a solar cell except that it operates at lower frequencies and thus may be configured to convert “earthshine” rather than sunshine into electrical energy. Earthshine is radiated from the earth at a mean wavelength of 10.5 microns (compared to sunshine at ˜0.5 micron). A photoconversion material may comprise a photo-sensitive bulk semiconductor and/or a metamaterial (man-made, non-natural materials) that may be better matched to the frequencies of the incident light than naturally-occurring materials and thus produce stronger photovoltaic or photocurrent effects. Photoconversion effects of various forms are accessible for all frequencies of incident light (electromagnetic radiation or photons) and all conductor/semi-conductor/insulator materials.